A prediction market lets you buy and sell contracts on the outcome of a real-world event — "Will the home team win tonight?" Every contract has a Yes side and a No side, and it trades at a price between 1¢ and 99¢.
When the game ends, the contract settles: the correct side is worth exactly $1, the wrong side is worth $0. So if you buy Yes at 60¢ and the team wins, each contract you hold pays $1 — 40¢ more than you paid. If the team loses, the contract expires worthless and you lose the 60¢.
That's the whole product. Everything else — order books, trading out early, price charts — is detail on top of that one mechanic.
A Yes contract trading at 60¢ means the market, as a group, currently thinks the outcome is about 60% likely. Here's why: if the true chance were higher, buying at 60¢ would be profitable on average, and buyers would push the price up. If it were lower, sellers would push it down. The price settles where the crowd's money balances.
That price moves continuously — like a stock — as news breaks, lineups change, and the game itself unfolds. A contract that opened at 55¢ can be 80¢ by halftime.
This is why BleacherBots publishes every prediction as a win probability: our model and a prediction market speak the same language. When our model says 61% and the market says 54¢, you can compare them directly — no conversion math.
The biggest practical difference from a traditional betting slip: a contract is a position you can trade, not a ticket you're locked into. Bought Yes at 40¢ and the price has climbed to 70¢? You can sell right now and keep the 30¢ difference — before the game is even decided. You can also sell to cut a loss when a position moves against you.
Nothing forces you to trade early, and selling into a live market means accepting whatever the current price is. But the option changes how people use these markets — positions get managed, not just placed and sweated.
Who you're trading against. On a prediction market, the other side of your trade is another person who disagrees with you. The exchange just matches you and takes a small fee. A sportsbook is the house: it sets the line and takes the other side of your bet itself.
How the price is set. Market prices come from an order book — the live balance of what buyers and sellers are willing to accept. Sportsbook lines are set and moved by the operator.
How they're regulated. Sports event contracts on exchanges like these are regulated federally as derivatives by the CFTC (the same agency that oversees commodity futures). Sportsbooks are licensed state by state by gaming regulators. That's also why prediction markets are available in many states that have no legal sportsbook.
What you hold. A tradeable position versus a fixed ticket, as covered above.
Different structure, same bottom line: it's real money at risk on an uncertain outcome. Treat it with the same discipline either way.
ProphetX — a sports-focused peer-to-peer exchange, operating as a CFTC-regulated designated contract market. You trade sports event contracts directly against other users at prices the order book sets.
Kalshi — a federally regulated (CFTC) exchange for yes/no event contracts. Sports is one category among many — Kalshi also lists markets on economics, weather, entertainment and more. 18+.
Novig — a peer-to-peer sports exchange where you trade against other fans at exchange prices rather than against a bookmaker.
Polymarket — markets on real-world events across sports, politics and culture. Its US product runs on a CFTC-regulated derivatives exchange and clearing organization. 18+.
Availability differs by state and by product — the card on this page shows what's actually open to you where you are, with each platform's full terms.
Prediction-market trading is real money at real risk. A contract can go to zero, which means losing your entire stake on that position. Prices can move against you fast, especially in-game. A 70% probability still loses 3 times out of 10 — a probability is not a promise, whether it comes from a market or from our model. Age and eligibility requirements vary by platform and by state, and each platform verifies them itself. Only trade with money you can afford to lose.
Every day our models — margin-adjusted Elo blended with Dixon-Coles and the de-vigged market consensus — publish a win probability for every game on the board, logged before the game and graded in public after the final. A prediction market gives that number somewhere to matter: if you think the market's price is wrong — or you think our number is wrong — you now know exactly what taking a position means.